PIOMAS September 2016

Another month has passed and so here is the updated Arctic sea ice volume graph as calculated by the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) at the Polar Science Center:

Weather conditions in the past month - the (Great?) Arctic Cyclone followed by the Mega-Dipole to be precise - have left a mark on volume decrease. During August 2016 more sea ice volume was lost than during any other August in the past decade, with the exception of 2008, even more than during August 2012 (2909 km3 vs 2744 km3). Just like on the area and extent graphs, 2016 is almost in second position here too, as the difference with 2011 shrunk from 621 km3 to 84 km3.

Here's how the differences with previous years have evolved from last month:

Last month I wrote:

There is a lot of melting potential in the East Siberian Sea region, extending into the Central Arctic, that could make this year end up close to the 2011 minimum, which is second lowest after the 2012 record lowest minimum.

We now know that melting has been massive in this region, as can be seen on this Uni Bremen SIC maps animation, showing the spectacular changes from August 2nd to September 2nd, the main reason for the significant volume drop:

Wipneus' version of the PIOMAS volume graph also clearly shows that this year's trend line dropped a bit faster, breezed past 2010 and is now almost at a par with 2011:

And so there's a small downtick again on the PIOMAS sea ice volume anomaly graph, which shows how much actual sea ice volume deviates from the linear trend, but not down to 2 standard deviation territory:

As for average thickness, here's the PIJAMAS graph based on my crude calculation of PIOMAS volume numbers divided by total JAXA sea ice extent:

2016 perfectly follows the new volume regime that started in 2010 and was interrupted during 2014 and 2015. The exact same can be seen on the thickness plot from the Polar Science Center:

So, can 2011 still be overtaken in the one or two weeks left in this melting season? 2011 reached the minimum on the earliest date in the past decade (September 10th) at 4302 km2. Sea ice volume is currently 4638 km3, so second place is definitely possible, but not easy, as in the past decade only 2008 and 2014 managed to lose the 336 km3 required until the minimum was hit. Added to that: the weather forecasts look like this melting season could end somewhat earlier, also given all that dispersed ice on the Pacific side of the Arctic, in what is now known as the Wrangel Arm.

But this also depends on how much longer bottom melt continues. Sea surface temperatures are really high, and this year is ending low, regardless of weather conditions it seems. Remember, during June and July very little sunshine reached the Arctic sea ice pack to create melt ponds and build up momentum for the remainder of the melting season. This was the kind of weather that made 2013 and 2014 stall, and prevented 2015 from going lower than it did.

Not this year, though. This year another kind of momentum carried things forward despite the weather. A mild winter, early opening up, extreme low snow cover, probably caused the Arctic to soak up enough heat to not care about the June and July sun. And who knows, maybe a pulse of warm water - extremely difficult to measure - from the Atlantic and Pacific continued the long-term process of complete Arctic sea ice loss.

The world hasn't experienced the warmest average global temperatures on record for three years in a row for nothing. This heat eventually ends up in the Arctic.

Comments

[viddaloo]

Thank you for this post, Neven. My PIOMAS estimate app already has 2016 @ 2nd lowest on September 1st.

As for the actual prediction skills of the Annual Average graphs, a couple of things are relevant. If the success criterium is a binary Top 3 / non–Top 3, this is of course way easier than the exact position @ minimum or the exact extent/volume of ice @ minimum. The other thing is what time of year an accurate prediction can be made, with September 1 being (too) easy and January 1 being extremely hard.

Rapid warming and melting of the Arctic makes only the past 10–15 years really relevant for predictions, IMO. Concentrating on the past decade, for extent only 13 and 14 failed to hit Top 3 @ minimum. 2014 was never in the Annual Average Extent (AAE) Top 3 low years throughout, and therefore easy to predict OUT. April or May would be sufficient to predict that. 2013 was more of a challenge, with June 1st as the earliest possible non–Top 3 prediction date.

For 2016 extent, March 1 @ 3rd lowest AAE and falling was a possible date for Top 3 minimum prediction, going more safe with April 1 @ 2nd lowest and falling.

Volume: In the last decade 2013–15 were the only exceptions to the rule that within a rapid downward trend, every new year will be in the Top 3 lowest @ minimum. Predicting their binary Top 3 status based on Annual Average Volume (AAV) alone, early in the season, was easier for the latter 2 years than for the former.

Much like for extent, 2013 couldn't be predicted OUT until June 1 from the AAV graph, at the very earliest. Yet after being lowest all year till then, and even since October of the previous year, something would have to be 'seriously wrong' about the melt momentum for AAV to start rising by June 1. By contrast, 2016 melt ponds & cloudiness in June never caused 2016 AAV to start rising, not even for one day. So this point supports the prediction strength of the June 1 AAV status.

2014 was never in the Top 3 low AAV years after mid–January, so Top 3 @ minimum could be ruled out early on, like March 1. For 2015 Top 3 low AAV was never even close, with 5th lowest in the first half of the year being its lowest, and going 6th in mid–May for the rest of the year. Top 3 @ minimum could be ruled out early on, like March 1.

For 2016 volume, 2015 of course caused its AAV to start 6th lowest. But going 5th in mid–January and falling consistently throughout the year (so far), made March 1 an early date for calling it IN the Top 3 low @ minimum. Safer of course by April 1. Forecasts for AAV on March 1 and April 1 pointed to a position in the Top 3 low AAV years by October–December. And thus at least a strong contender for Top 3 @ minimum.

In summary: Top 3 @ minimum for 2016 was predictable from Annual Average graphs as early as March or April for both volume & extent.

(Now, the *real* test for this method will of course be the first new year after its inception, ie 2017. Will it need editing or modification? Perhaps, but probably not, as the exceptional years 2013 to 2015 have provided sufficiently diverse cases for the prediction of minimum non–Top 3 years.)

[William Crump]

viddaloo I like your analysis but why narrow the focus to top 3? Wouldn't a prediction of top 5 have a higher probability of success and be every bit as effective as a prediction of the declining state of the ice?

Can someone with far better skills than I have do a graph showing how the five year moving average has changed over the last five years? The focus on single year numbers is weather, not climate. Looking at five or better yet, changes in decade averages is a better measure of a climate trend.

[William Crump]

The PIOMAS volume vs extent graph appears to indicate that the thickness of Arctic ice has stabilized.

This is to be expected as most of the thick multi-year ice has disappeared from the Arctic.

I believe this chart supports the position that the Central Arctic Basin ice will last longer than extrapolations based on Arctic wide data indicates it will last.

[D]

The persistent storminess over the Arctic ocean increases the influx of Atlantic water to the Arctic through the Barents sea. On the other side of the Arctic this summer's winds and currents have reduced the influx of Pacific water. In 2012 winds helped push Pacific water into the Arctic and drove Arctic sea ice out through the Fram. This summer there were anomalous winds blowing from Greenland towards the new Siberian Islands.

There's a lot of excess heat in the north Pacific but it's effects on the Arctic would be mostly atmospheric by increasing water vapor levels and temperatures.

-Fish

[navegante]

PIOMAS is clearly overestimating thickness along the Wrangel arm, even in areas where satellites show very low ice concentration, with most ice floe sizes below the 250m resolution of MODIS.
Expect PIOMAS minimum under 2011 as soon as the model assimilates the melt out of these ice extensions (if only).

[navegante]

On the other side of the Arctic this summer's winds and currents have reduced the influx of Pacific water
Yes, this may explain the current overabundance of ice at Beaufort sea, Chukchi sea, and ESS.

[Neven]

PIOMAS is clearly overestimating thickness along the Wrangel arm, even in areas where satellites show very low ice concentration, with most ice floe sizes below the 250m resolution of MODIS.
Expect PIOMAS minimum under 2011 as soon as the model assimilates the melt out of these ice extensions (if only).

I agree, navegante, that whether 2016 will go below 2011, will largely depend on what happens to the ice in the Wrangel Arm.

As you can see on this thickness anomaly map that is also posted on the PSC PIOMAS website, that zone is still considered to have a lot of volume, in comparison to the 2000-2015 average (click for a larger version):

If that red blob north of Wrangel Island goes, volume might dip just low enough to overtake 2011.

But I'm not sure if all the ice will disappear, given the current weather forecast.

[Bill Fothergill]

Neven,

There appears to be a small typo just below your PIJAMAS graph. You have a sentence which includes...
"... volume regime that started in 2010 and was interrupted during 2014 and 2016 ..."

Should that read "2014 and 2015"?

[viddaloo]

"First, since the summer sea ice was also shrinking, this meant that the summer ice cover had lost something like 60 per cent of its volume between the 1970s and the 1990s, a far more drastic and dramatic loss than one would have suspected without taking account of the ice thickness. At this rate the summer ice would disappear fairly early in the coming twenty-first century. The world needed to be warned, and we did our best to warn it. But not only did the politicians and industrialists not want to know, neither did the scientific modellers. They continued to run unrealistic models which forecast that sea ice would remain substantially undiminished right up to the end of the twenty-first century. The UK Meteorological Office still clings to these impossible predictions. Nature would soon prove them wrong."

A Farewell To Ice, p. 69, Wadhams 2016

[Neven]

Should that read "2014 and 2015"?

Yes, it should. Thanks, Bill. Fixed now.

Thanks for the excerpt, vid. I might go and buy that book.

[Hans Gunnstaddar]

http://www.iup.uni-bremen.de:8084/amsr2/Arctic_AMSR2_nic.png

I'm wondering if that big chunk of ice pointing towards the Laptev from the NP, could get drawn all the way across to join up with the more organized ice hugging the Canadian Archapeligo. If so, wouldn't extent decline sharply?

[wayne]

Hans

The larger question would be if we have any idea of the true melt removing the 15% threshold. Of course if the ice you cited moved and compacted towards Canada the extent would be equal to 2012, but in here we need another calculated 2nd opinion.

[Jim Hunt]

JAXA extent has dropped to 4.05 million km²:

http://greatwhitecon.info/2016/09/the-2016-arctic-sea-ice-metric-minima/#comment-215516

That's just below the 2007 minimum and second lowest with a big gap to the 2012 minimum of 3.18 million km².

How much compaction will take place from here to the 2016 minimum remains to be seen!

N.B. Hans' Bremen link looks rather the worse for wear this morning.

[John Christensen]

Thank you for another great update Neven!

Based on the weather forecast with reduced barocline and the weak low situated with of the CAA, I would expect volume reduction to get rapidly reduced and therefore that 2016 will stay above 2011, at least measured by end of Sept.

[wayne]

Jim,

"That's just below the 2007 minimum and second lowest with a big gap to the 2012 minimum of 3.18 million km²."

And that is with contrarian wind to Trans Polar Stream dispersing sea ice differently, which temporarily slows the melt rate:

http://eh2r.blogspot.ca/2016/09/wrangel-bridge-waves-away-goodbye.html

Next stop is breaking the 4 million barrier and beyond. How many models are left being right? Revisions gentlemen?

[Jim Hunt]

A glimpse through the fog and clouds of the dispersion at the North Pole this morning:

http://GreatWhiteCon.info/2016/09/could-northabout-sail-to-the-north-pole/#Sep-04

[Hans Gunnstaddar]

"N.B. Hans' Bremen link looks rather the worse for wear this morning."

So noted, and it looks like that may have caused errors in some of the extent graphs because one has 2016 extent all the way down near 2012's low.

[wayne]

Jim,

The larger look revealed what I always feared, a very fluid Transpolar Stream Current all the way to the North Atlantic,
because of this, I am almost tempted to call 2016 #1 minima:

http://eh2r.blogspot.ca/2016/09/transpolar-stream-current-is-now-free.html

[Rob Dekker]

I find the PIOMAS update on ice volume a lot more believable than the DMI ice volume update :

http://polarportal.dk/fileadmin/polarportal/sea/CICE_combine_thick_SM_EN_20160904.png

Note the sudden drop in ice volume from 'average' to almost record low in the second half of August.
This while in 2015, over the same period, DMI suggested that ice volume was increasing rapidly.

With such fluke adjustments (undoubtfully caused by assimilation of actual ice concentration observations) DMI's volume graph is mostly providing fodder for climate science deniers (as it DID last month), and is a hassle for the rest of us trying to explain that DMI's volume data should be taken with a grain of salt.

I wish DMI would simply report PIOMAS numbers and discard their own mediocre volume product.

[viddaloo]

With both Wipneus & Uni-Bremen moving house, I've decided to take a short(ish) holiday. Ice addiction is after all not good and may cause hypotermia.

[wayne]

Of course sea ice flows wildly differently given the current Arctic icescape, a case in point would be the effect of liquefaction of the Transpolar Stream:

http://eh2r.blogspot.ca/2016/09/some-effects-of-open-water-transpolar.html

Extent numbers varying wildly were expected with the changing winds as well.

[Jim Hunt]

Viddaloo - Bremen are back at work already:

http://GreatWhiteCon.info/2016/09/the-2016-arctic-sea-ice-metric-minima/#comment-215549

[Kevin McKinney]

Quite the finish to the melt season! How low can it go? Guess we'll soon know, but this is 'spectacular', all right.

[Hans Gunnstaddar]

Is there an extent low winner yet between 2007 & 2016? Drum roll...

[Bill Fothergill]

@ Hans
"Is there an extent low winner yet between 2007 & 2016? Drum roll..."

We clearly won't know how the September average extent numbers are going to stack up for some time yet. However, if you are simply referring to absolute minimums, then the answer is "it depends"...

University of Bremen - Yes
http://www.iup.uni-bremen.de:8084/amsr2/extent_n_running_mean_amsr2_regular.png

DMI - Don't know
http://ocean.dmi.dk/arctic/icecover.uk.php

NSIDC 5-day Charctic - Don't know
http://nsidc.org/arcticseaicenews/charctic-interactive-sea-ice-graph/

Arctic ROOS (Nansen Environmental) - Don't know
http://arctic-roos.org/observations/ice-area-and-extent-in-arctic

JAXA/ADS - Yes
https://ads.nipr.ac.jp/vishop.ver1/vishop-extent.html?N

Of course, the 2 "Yes" responses are subject to the caveat that they are not subject to an upward revision - as per what happened to the DMI plot a couple of days ago.

It may be that some bright spark has access to an old DMI or ROOS plot that still shows the 2007 values. In this case, an overlay might be revealing

[Jim Hunt]

Bill - Don't forget the high res AMSR2 numbers from Wipneus and the University of Hamburg:

http://GreatWhiteCon.info/2016/09/the-2016-arctic-sea-ice-metric-minima/#Sep-04

They also now have 2016 below 2007, especially for area!

[Jim Hunt]

Arctic sea ice volume is mentioned in this new podcast in which Peter Wadhams, professor of ocean physics at Cambridge University, debates Arctic sea ice decline with Dr David Schroeder from the Centre for Polar Observation and Modelling at Reading University and Jonathan Bamber, professor of physical geography at the University of Bristol:

https://www.theguardian.com/science/audio/2016/sep/06/the-fate-of-arctic-sea-ice-science-weekly-podcast

[wayne]

It is definitely #2 by all means, much more if it wasn't for the 15% per grid rule:

http://eh2r.blogspot.ca/2016/09/a-lot-of-confusing-action-explains.html

This is where extent numbers slip on the reality sea icy road. Take a look and find that there is a lot of shattering going about.

[wayne]

There is great melting still going about as seen by Goodbye Waves, but it is also masked by great dispersal of broken up thinner sea ice especially by the Ostrov Komsomolets ice bridge which is literally breaking apart fast with very little wind:

http://eh2r.blogspot.ca/2016/09/np-to-ostrov-komsomolets-once-ice.html

[wayne]

The only cold area is in the CAA-North Greenland region, elsewhere, quite warm does not seem to give melting results, but its all masked under massive dispersion of vast areas of loose sea ice packs spreading outwards. Examples abound:

http://eh2r.blogspot.ca/2016/09/atlantic-front-franz-josef-lands.html

There is also some great noise action North of Greenland:

http://eh2r.blogspot.ca/2016/09/recoiling-sea-ice-sea-ice-momentum.html

The densest pack is de coiling.

[Hans Gunnstaddar]

http://nsidc.org/arcticseaicenews/

Latest report: September 7th, 2016

'Arctic sea ice nears its minimum extent for the year'

Throughout August, Arctic sea ice extent continued to track two or more standard deviations below the long-term average. The month saw two very strong storms enter the central Arctic Ocean from along the Siberian coast.

Average sea ice extent for August 2016 was 5.60 million square kilometers (2.16 million square miles), the fourth lowest August extent in the satellite record. This is 1.03 million square kilometers below the 1981 to 2010 average for the month and 890,000 square kilometers (344,000 square miles) above the record low for August set in 2012. As of September 5, sea ice extent remains below average everywhere except for a small area within the Laptev Sea. Ice extent is especially low in the Beaufort Sea and in the East Siberian Sea. With about two weeks of seasonal melt yet to go, it is unlikely that a new record low will be reached.

However, since August 26, total sea ice extent is already lower than at the same time in 2007 and is currently tracking as the second lowest daily extent on record. In addition, during the first five days of September the ice cover has retreated an additional 288,000 square kilometers (111,000 square miles) as the tongue of sea ice in the Chukchi Sea has started to disintegrate.

It indeed appears that the August 2016 storms helped to break up the ice and spread it out, contributing to the development of several large embayments and polynyas. Some of this ice divergence likely led to fragmented ice being transported into warmer ocean waters, hastening melt. Whether warmer waters from below were mixed upwards to hasten melt remains to be determined, but as discussed below, these storms were associated with very high wave heights.

[Sarat]

What a year for the arctic ice, and now it looks like the La Nina relief will not come. Another warmer than average winter may be in the cards...

http://mashable.com/2016/09/08/la-nina-watch-canceled-global-warming/

[Jim Hunt]

Furthermore the daily NSIDC extent has now dropped to 4.083 million km², which is below the 2007 minimum:

http://GreatWhiteCon.info/2016/09/the-2016-arctic-sea-ice-metric-minima/#comment-215597

Whether the 5 day trailing average follows suit remains to be seen.

[AbbottisGone]

If i may quote NSIDC:

Northwest Passage update

Figure 5. The time series shows total sea ice area for selected years and the 1981-2010 average within the northern route of the Northwest Passage. The cyan line shows 2016 and other colors show ice conditions in different years. Data are from the Canadian Ice Service.

Credit: Stephen Howell, Environment and Climate Change Canada
High-resolution image

The Northwest Passage refers to the fabled shortcut between the Atlantic and Pacific through the Canadian Archipelago. However, it is not one route. There is a northern, deep-water route through the Parry Channel, entered from the west through the M’Clure Strait and a shallower southern route, known as Amundsen’s route. Sea ice in the Parry Channel route has shown a sharp decline since the middle of July, but the channel is still not entirely ice free. Considerable ice remains in the western (M’Clure Strait) region and there are lesser amounts in the eastern regions. This is mostly (~80 percent) multiyear ice. Low ice years in the Parry Channel are typically the result of early summer breakup associated with high sea level pressure over the Beaufort Sea and Canada Basin that displace the Arctic Ocean pack ice away from the western entrance. Conversely, low sea level pressure anomalies over the Beaufort Sea and Canada Basin keep the Arctic Ocean pack ice up against the western entrance. This has been the case for much of the 2016 melt season. The southern (Amundsen’s) route is open but it is still uncertain whether the northern route will open in the coming weeks.

Even during mild ice years, thick multiyear ice is typically advected into these routes during the summer months. Multiyear ice is a significant obstacle for ships. Nevertheless, taking advantage of mild sea ice conditions, the 68,000-ton Crystal Serenity set sail from Anchorage, Alaska on August 16 for its 32-day journey through the Northwest Passage via Amundsen’s route. This is the largest ship thus far to navigate the Northwest Passage and is accompanied by an icebreaker ship and two helicopters. The ship sailed through the Northwest Passage in less than three weeks—52 times faster than Amundsen’s nearly three-year voyage.

On the other side of the Arctic, the Northern Sea Route appears mostly ice free.

<<

I find this most en-heartening that we all care. Tally-ho chaps et al.

[AbbottisGone]

Wayne,
you are a very solid contributor to the forum- much more than I could ever hope to be- but I must say that measurement problems are measurement problems and the 15% rule will always be allowed to wear my guernsey ;>'///<

[wayne]

Hi AbbottisGone,

Wears me down too, I am astounded that they use it, therefore every time I see this flaw interfering with a sound analysis, I will mention, perhaps bad methods will change if we keep repeating, and then I would be most glad to see it gone, and dish out more mistakes till they end.

[wayne]

more like point out , rather than dish out.

Case in point today, an increase in extent, all be it very small, despite significant evidence of melting. If this minima per grid was removed, if we measured water or ice by the maximum equipment resolution possible, there would be better prognostics and subsequently forecasting.

[Rob Dekker]

Wayne, the 15% rule for extent is reasonable, given that the satellite observation error is in that same ballpark.
If they would lower that threshold, you would see a lot of "false ice" interfering with the data.
Also, regardless of the level (15% or 20% or 30%), if the same threshold is used for all historic data, you can make a fair comparison between years. And that is exactly what NSIDC data provides.

[wayne]

Hi Rob

Very long ago 15% per 16 km would have been passable, now we have satellites with 1 meter resolution. Using this method there is no reasonable comparison between a year such as 2016 2013 vs 2012 2007. Expansive vs compressed, it is a fallacy to say that 2016 has more extent than 2012. Because 2012 ice field was compressed and 2016 more dispersed. A true measure would be to use highest resolution possible, something like black pixel water white pixel ice, or more to date: solid echo ice liquid echo water, disregard Area and Extent and simply use purest sea ice coverage possible, 80% sea ice coverage per entire area or Ocean. Back verification with lower resolution historic data may be recalculated like we colorize old black and white films one pixel at the time. There is no excuse to use archaic methods which were once reasonable now should be considered backwards.

How to rationalize data which inherently have flaws induces automatic errors. There is no reason to stipulate one grid having 15% sea ice as valid and comparable to a grid with 100%.

There is sea ice or no ice , that is all. Forecasting that there will be 4 million km2 consisting of grids at 15 to 100% is hallucinogenic. Therefore I forecast un-likewise, there is more ice or less ice, and 2016 if you compress it all, has very likely less ice than 2012.

[viddaloo]

That's all very interesting, Wayne. But is there any chance for a formal calculation of ice numbers from your suggested method? We may need that sooner than we think, if 2016 melt patterns are becoming the new normal.

[wayne]

Hi viddaloo

Yes, the new normal is dispersion rather than compaction, how do we compare the 2 types of geometric action influencing melting rates without confusing ourselves?

http://eh2r.blogspot.ca/2016/09/dispersion-of-very-melted-broken-up-sea.html

I believe the old 15% rule was designed greatly for a periphery analysis at the edge of an existing huge pack ice area largely surviving the summer. Now the Pack is collapsing within.

A high resolution pixel by pixel analysis is a far better way to judge melt rates now a days.

[Kevin O'Neill]

Rob Dekker writes: "Also, regardless of the level (15% or 20% or 30%), if the same threshold is used for all historic data, you can make a fair comparison between years. And that is exactly what NSIDC data provides."

This is the standard response, and for some metrics it is a valid response, but for some measurements it is totally inaccurate.

Essentially it is only valid when *all other variables are equal.* Now, would anyone like to make *that* particular claim?

The two most important factors that I can see off the top of my head are the distribution of ice by concentration and the variance of same. In high concentration regimes an error of 15% is not going to change anything. In low concentration regimes it can change alot.

One need only consider how the 'pole hole' is treated. I believe it is assumed to be 100% -- because that made sense 40 years ago. Does it make any sense *this* year? We are suddenly no longer comparing like-to-like, but actually introducing error by using an unchanging metric.

When marginal ice zones make up a small percentage of the overall extent, then the arbitrary threshold is of little importance, but in years where the marginal ice zones are widespread, then the arbitrary threshold becomes misleading.

It is mistaken to believe that any arbitrary threshold allows one to compare the past and present given the other changes that have taken place.

[Kevin O'Neill]

wayne writes: "I believe the old 15% rule was designed greatly for a periphery analysis at the edge of an existing huge pack ice area largely surviving the summer. Now the Pack is collapsing within."

Yes, this is exactly the same thing I wrote (not having read wayne's comment yet) about the marginal ice zones. The marginal ice zones used to be on the periphery of the pack. Now they're just about everywhere.

[fryingpan136]

I agree with those questioning the usefulness of the extent statistic. The 15% threshold is utterly arbitrary. I think area is a more useful metric than extent. I agree that "a high resolution pixel by pixel" count sounds most accurate. I am surprised extent is followed so closely, considering a strong wind can significantly affect extent without affecting area or volume.

While area is important for determining how much of the sea surface is exposed, volume seems by far the most important metric. I understand that volume us harder to measure, and so less reliable volume data is available. I always look forward to the PIOMAS updates, as I feel they say the most about the condition of the ice.

[fryingpan136]

Edit: Polar bears might disagree that volume is more important than extent and area.

[Rob Dekker]

Kevin wrote :

Yes, this is exactly the same thing I wrote (not having read wayne's comment yet) about the marginal ice zones. The marginal ice zones used to be on the periphery of the pack. Now they're just about everywhere.

Maybe sea ice "area" is a better metric than "extent" for the sort of analysis that you and wayne are suggesting.

[Kevin O'Neill]

Rob Dekker writes: "Maybe sea ice "area" is a better metric than "extent" for the sort of analysis that you and wayne are suggesting."

I think you're missing the point. If we want to compare two periods we want an appropriate comparison; i.e, apples-to-apples. If we know there are discrepancies that the comparison does not take into account we should either attempt to correct them or heavily caveat the comparisons.

Blithely assuming that the measurement process has not changed therefor the comparison is apt is wrong. It's the assumption that the comparison is apt that is the problem - not whether another metric is more or less apt.

We *want* useful comparisons for historical reasons, but at some point we have to assess whether systemic changes invalidate or significantly affect the comparison; i.e., does it become misleading.

It is unclear to me that area actually offers a more valid comparison. If it did, I think scientists would use it instead of extent. Extent may be the best metric we have - that doesn't imply that the process results are immune from a growing systemic bias.

[Jim Hunt]

FryingPan et al. - One well known problem with area is that in summer the satellites/algos confuse ice covered with melt ponds with open water. According to the NSIDC:

Scientists at NSIDC report extent because they are cautious about summertime values of ice concentration and area taken from satellite sensors. To the sensor, surface melt appears to be open water rather than water on top of sea ice. So, while reliable for measuring area most of the year, the microwave sensor is prone to underestimating the actual ice concentration and area when the surface is melting. To account for that potential inaccuracy, NSIDC scientists rely primarily on extent when analyzing melt-season conditions and reporting them to the public. That said, analyzing ice area is still quite valuable. Given the right circumstances, background knowledge, and scientific information on current conditions, it can provide an excellent sense of how much ice there really is “on the ground.”

That said, with much of the Arctic currently looking like a marginal ice zone (MIZ for short) the final sentence seems to become more relevant with each passing year. By way of example see:

http://GreatWhiteCon.info/resources/arctic-sea-ice-images/summer-2016-images/#NorthPole

[Lord Soth]

Here is a picture from the North Pole, with the Swedish Ice Breaker ODEN moored to an ice flow on August 28th, 2016.

https://twitter.com/ccg_gcc/status/769867469628596224

The Swedish ICE Breaker ODEN and the Canadian Ice Breaker Louis St. Laurent is doing a Joint Arctic Survey in the High Arctic.

[John Christensen]

On measuring 2016 against 2012 melt:

Due to the known issue of melt pond interference on ice area measurements during the above freezing air temp period -roughly June-August - it makes sense using the ice extent measurement to track development in the high summer period.

However, now that temperatures above most of the sea ice covered area (I would not call this an 'ice pack' anymore), you can use ice area (as well as ice volume) to measure overall ice melt of the melting season just passed.

For ice area, using ROOS or the Pettit graph, we see that by late April the ice area of 2012 was about 1,000,000KM2 larger than in 2016, but that for ice area minimum we are currently about 450,000KM2 above the 2012 ice area minimum.

This corresponds well with the development in PIOMAS ice volume from end-April to now: 2012 had more volume than 2016, but by September, 2012 had less volume.

These numbers - and disregarding any speculation on degree of influence by low ice concentration - leads me to conclude that 2012 saw stronger melt than 2016 and that therefore this year did not prove to be the strongest melt in history.

[Jim Hunt]

For those who favour extent, the NSIDC 5 day trailing averaged extent has now joined the daily value in 2nd place below the 2007 minimum, but still well above 2012, at 4.146 million km²:

http://GreatWhiteCon.info/2016/09/the-2016-arctic-sea-ice-metric-minima/#comment-215618

[Tor Bejnar]

Jim Hunt (@13:48) and John Christensen (@15:22) speak my mind. (Thanks!)

[Wayne Kernochan]

I can't resist delurking to comment on Lord Soth's picture. Does anyone else remember when I got into a heated argument with someone who maintained that North Pole ice would not melt for a long time, if ever? I would guess that his argument was that it was so thick at the North Pole that the melting season was too short to entirely melt it. I think it was in 2012 ...

I know there's a German word (schadenfreude) for feeling pleasure at the sorrows of others. Is there one for feeling happy about being right while sad that it's come to pass?

[D]

John C's analysis sounds a lot like science. This summer there were anomalous winds blowing from Greenland across the pole & towards the New Siberian islands. Not only was July 2012 sunnier than 2016 but there was far more ice export through the Fram and far more flow of warm Pacific water through the Bering strait.

This summer's weather patterns were not particularly favorable for melting. In 2016 the warm winter and the intense Beaufort high in May led to low September ice. It is disturbing that the ice is in such poor shape after a summer that was so favorable for ice retention.

This year melting from below has played a much bigger role relative to 2012 where massive melting from above was driven by warm sunny weather.

-Fish

ps The resurgence of very warm water into the subarctic seas is not a good sign for ice in the years ahead.

[Bill Fothergill]

@ Wayne K
"Is there [a word] for feeling happy about being right while sad that it's come to pass?"

Can't think of one that exactly fits the bill, but what you're describing could be referred to as a "Pyrrhic victory".

https://en.wikipedia.org/wiki/Pyrrhic_victory

[Hans Gunnstaddar]

Thanks Jim for the graph confirming extent is 2nd this year.

Does anyone have a link or list of exact minima's in million km2, for years 2007 through 2015? I tried a search but came up snake eyes. I need to forward it to a friend doing a short YouTube video with a projection for 2017 minima. Should prove to be good theatre and an interesting prediction based on...well, you'll just have to wait for the rationale.

[wayne]

D

Science? Let us see

If you ignore that out of 1 million km2 of 100% sea ice allegedly measured by 15% extent or area rule, can have up to 850,000 km2 of open water, if you ignore your own eyes and mind about what dispersed sea ice would look like if it was all compacted like during a compacted year, anything can be led to speculation, sure sounds like precluded science with emotions overtaking facts. I rather have the facts recalculated before making a rush for a conclusion.

Weather didn't matter so much, and those who adhere to that love speculation.

[Bill Fothergill]

Hans,

The Arctic Sea Ice Graphs link (near the top right of every article on this blog, just below the Hiroshima Bombs counter) provides a wealth of links to individual data sets.

Can't your friend extract the necessary data from that?

[Jim Hunt]

Your friend is in luck Hans. I happen to have a (daily) NSIDC spreadsheet open in front of me:

2007 4.1607
2008 4.55469
2009 5.05488
2010 4.59918
2011 4.33028
2012 3.36973
2013 5.07709
2014 4.98339
2015 4.341
2016 4.083 (to Sept 8th)

E&OE

[wayne]

The problem with having 850,000 km2 potential error per million square Kilometers is not so seriously catastrophic if there was compaction. It is very serious if there is dispersion, like this year. We are merely talking about 2.55 million square kilometers per 4 million margin of error.

Alas , those who like this measurement scheme, ultimately fail in predictions, because there is so much ice or water which is or isn't there.

Making room for contrarians to play and have fun is bad science. We must get serious and measure sea ice at the limits of our capacity. Otherwise, it will always be a "blame the weather" to and fro. All when it is really AGW gripping our atmosphere into a ever so increasing warming build up.

[viddaloo]

Still on holiday from the ice, but I think Wipneus would be the only one who could produce the more exact numbers Wayne is wishing for. Technically, that is.

It needs to be instrumentalised into numbers using a consistent method of counting the grid cells, for it not to be subjective.

Re-entering holiday mode :)

[G man]

Well looks like the end is near/here with multiple agencies showing leveling off or increases. Another year and the sea ice remains. Temps are plummeting. And even with one of the lowest pressuresystems "ever" measured and the "mega dipole" the sea ice lived to tell the story. The only drama left is whether the Northabout Polar Challenge can make it through the "disappearing" sea ice at the entrance to Lancaster Sound and freedom out to Baffin Bay.

[wayne]

thanks Viddaloo

Wipneus does great work, may be he has the software and computing power. Enjoy the holidays, hopefully with plenty of snow and lake ice to jump from between saunas:)

[Bill Fothergill]

@ G man
"...The only drama left is whether the Northabout Polar Challenge can make it through the "disappearing" sea ice at the entrance to Lancaster Sound and freedom out to Baffin Bay."

Well, she passed through the potential ice choke point at the Bellot Strait several hours ago, and was going at a fair rate of knots. Looking at the latest Eastern Arctic ice charts from the Canadian Ice Service, I don't think the crew will exactly be shitting themselves.

I'm more interested in what a certain Tony Heller will be coming out with next.

[Jim Hunt]

You and me both Bill! The race for the 2016 "New Einstein" award is hotting up:

That is your justification for snuffing out 21,000 innocent humans every day?

Your mental illness is abundantly evident Jim.

Please, do go on Jim, you criminally insane alarmists have so much to share with the rest of us.

[G man]

Bill, they've had smooth sailing since they left the Laptev for the most part. Bellot was wide open. The southern route through Fury/Hecla is just about shut down and the entrance from Prince Regent sound to Lancaster Straight is getting icy. We'll see how icy about this time tommorrow. Hopefully they stocked up on TP in Tuk.

[Jim Hunt]

That's not quite how they described it G man! Not much in the way of ice, but in the Chukchi:

http://GreatWhiteCon.info/2016/08/northabout-races-for-the-date-line/#Aug-29

We are into the second day of 25 to 30 knot winds, throwing the boat around and everything in it. Many people are feeling queasy and not managing to eat very much. We are being thrown around in the saloon whenever we try to do anything, such as make a cup of tea or cook dinner. I for one feel ill, weak (through not eating enough), and slightly sick all of the time.

and in the Beaufort:

http://GreatWhiteCon.info/2016/08/northabout-braves-the-northwest-passage/#Aug-30

The weather forecast is pants. A 30/35 knot headwind along the coast . No one has the appetite for it, so we are heading North, slacker winds, staysail out, still a choppy sea and uncomfortable, but not as bad as 30 knots.

Then their auto-helm broke.

[Hans Gunnstaddar]

Thanks for the numbers, Jim! I shall pass them on.

[John Christensen]

"If you ignore that out of 1 million km2 of 100% sea ice allegedly measured by 15% extent or area rule, can have up to 850,000 km2 of open water"

I really do not want to start any further argument with you wayne, but please review the calculation for SIA and reconsider your statement above:

"Ice area is the sum of the grid cell areas multiplied by the ice concentration for all cells with ice concentrations of at least 15%."

http://arctic-roos.org/observations/ice-area-and-extent-in-arctic

[Jim Hunt]

John - I think you'll find Wayne is referring to the extent calculation, not area.

100% - 15% = 85% open water which would be classified as 100% ice for extent purposes.

Have you checked out the North Pole area recently? If not please see:

http://GreatWhiteCon.info/resources/arctic-sea-ice-images/summer-2016-images/#NorthPole

and then contrast it with:

http://nsidc.org/data/seaice_index/images/daily_images/N_daily_extent_hires.png

[wayne]

Amazing capture Jim,

Its dispersing quickly + melting at the same time, if it expands a little more may be the 15% grids will diminish. Nothing is easy with sea ice. I would say a lot of salty sea ice with melting points between -1 and -2 are just about gone by now, what is left is top sea ice with melting point closer to 0 C.

[wayne]

http://eh2r.blogspot.ca/2016/09/plenty-of-melting-not-that-it-shows.html

I rather show what is really going on, if we are not careful, we may think that freeze-up has started! Not so, just a lamentable destroyed state of once upon a time solid dense wide covering sea ice. Goodbye Waves prove otherwise as well, melting continues.

[wayne]

this works…

http://eh2r.blogspot.ca/2016/09/plenty-of-melting-not-that-it-shows_10.html

[Rob Dekker]

wayne said

It is very serious if there is dispersion, like this year. We are merely talking about 2.55 million square kilometers per 4 million margin of error.

As noted before, if you are concerned about the margin of error that the sea ice "extent" metric causes due to ice "dispersion", then please, my all means, switch to sea ice "area".

After all, sea ice "area" is indifferent to ice dispersion, and especially now that the melting ponds are freezing over, provides a good metric for how much ice there is in the Arctic.

[wayne]

Rob

Sea ice area has the same 15% thing....

[Neven]

Sea ice area has the same 15% thing....

Which means that everything below 15% is considered zero. But unlike extent - where everything above 15% is considered 100% covered - it's not an either/or proposition (either 0% or 100%).

Every metric is useful, and no metric is the Holy Grail. We saw the same kind of dispersal in 2010 and 2013, and at the time I calculated how much lower extent would be if the holes within the pack were counted. It was somewhat lower, but not hugely so.

If someone can quantify for this year, that would be nice, but don't expect this year to be as low or lower than 2012, because Wipneus' AMSR2 SIA (3.125 km resolution) clearly shows this year to be higher.

Speaking of which: I hope Wipneus' move to his new home has proceeded in orderly fashion, and he can soon resume the magnificent job he's doing. I'm starting to miss his data!

[viddaloo]

Well, we all miss Wipneus' data very dearly, at least I am, although there's something to be said for taking a holiday from everything (new angles, ideas, experience (even unrelated to ice, OMG)).

Having said that, it's already abundantly clear that 2016 went a lot lower than 2012, 2007 and any of the other players, the only question remaining is whether it will also go lowest ever for the one–day minimum measure, which seems disputed, and for which there will be no definite answer, I think, before the middle of October, or when PIOMAS figures for October finally arrive in November.

For year–to–date and 365–day annual averages 2016 is much lower than 2012, except for PIOMAS volume, where some people expect some form of correction to the PIOMAS model, reflecting the different face of Arctic sea ice.

[Jim Hunt]

Vid - It is abundantly clear to me that 2016 hasn't already gone "a lot lower than 2012" on any of the numerous metrics I am avidly following, including Wipneus' data:

http://GreatWhiteCon.info/2016/09/the-2016-arctic-sea-ice-metric-minima/

Please could you clarify your remark?

[Jim Hunt]

Rob/Neven - Were Wipneus already back online I suspect he would confirm that the late, lamented CT area metric did not in actual fact use a 15% threshold.

[Neven]

Please could you clarify your remark?

Jim, vid refers to 'year–to–date and 365–day annual averages'. Tamino also has some graphs in this latest blog post.

[John Christensen]

Hi Neven,

You said: "at the time I calculated how much lower extent would be if the holes within the pack were counted"

What is the benefit of removing the holes within the pack from the extent number compared to using the area number, which in principle should do just that?

[Jim Hunt]

Neven - I saw that, but it's at the end of Vid's comment. He opens with "Wipneus' data".

Bill - I already have at least a partial answer to the question you posed yesterday:

"Dumb and Dumberer at the Blog of Fools"

I hope that's all OK with you, and that you find it at least moderately amusing? I feel sure that the best is yet to come!

[wayne]

Hi Neven,

Bring your artistic geometric self out, canvas not needed, but artist hat is necessary! Take 2016 exceeding protruding areas to fill its greater than 2016 open water gaps. It should give about the same overall area as 2012, except the sea ice far less denser in 2016 in many sectors.

"Which means that everything below 15% is considered zero. But unlike extent - where everything above 15% is considered 100% covered - it's not an either/or proposition (either 0% or 100%)."

There should be less sea ice area than extent by this method. But 16% sea ice per grid (there are many similar this year) gives 84% more ice for free. How esoteric hey?

I will never accept these silly rules of dedicated for pre 1980's sea ice periphery. Especially since we can do better. I study these numbers because they are the only ones published.

Here is an idea, compare 2016 sea ice area with 2012 extent, and you get a better image of 2016 . Its very rough, but far better comparison.

[wayne]

Take 2016 exceeding protruding areas (compared to 2012) to fill its greater than 2012 open water gaps.

[Hans Gunnstaddar]

https://www.youtube.com/watch?v=OdWyrVZWz_E

Thanks to a good buddy C. Nevell Slater, author of 'The Theory of Opposite Sub-Verses' (a great theory by the way), here's a YouTube video of my extent minimum prediction for 2017, followed by 2 week interval images of this year's melt via Bremen.

I know it's a simple prediction so let's not get too reactionary to it, and just see how accurate it may be come next melt season.

[Lord Soth]

Although, the laws of thermodynamics, guarantee an ice free arctic sometime this century, natural variability prevents us from predicting when it will occur.

We are living in interesting times, as per the Chinese Curse, or in this case during the early stages of the Holocene-Anthropocene Thermal Maximum.

[viddaloo]

For Hans: https://i.imgur.com/ONjWhgc.jpg

PS: I have no idea how to make an image 400 px wide using only Imgur and an iPad. I was allowed to copy the link to the image and that's wow in these days, I think. I didn't have to use pen & paper as a go-between.

[Hans Gunnstaddar]

Thanks viddaloo for postingt the graph - wow, even 2002-2006 was in a similar pattern! I think you had posted it before but at the time could only get part of it on my screen. Nice to have the whole thing. It is analogous to breathing like the drowning man, and suggestive 2017 will probably set a new record minimum. Fascinating but terrifying.

[John Christensen]

" even 2002-2006 was in a similar pattern!"

I saw the graph also - great image viddaloo - but the pattern prior to 2007 does not seem to have the drop and increase that we saw in 2007/08 and 2012/13..

[Neven]

Chris Reynolds also just posted about an oscillation in August extent loss.

[Neven]

Unfortunately, some very sad news. It seems Andrew Slater has died unexpectedly. I'm at a loss for words right now, but I'll try and write something later this week.

[John Christensen]

I am very sorry to hear the sad news about Andrew Slater, he seemed much too young and energetic to be leaving us.

[Hans Gunnstaddar]

"but the pattern prior to 2007 does not seem to have the drop and increase that we saw in 2007/08 and 2012/13.."

True, JC. I should have mentioned that was in reference to the latter part of the pattern.

[Hans Gunnstaddar]

http://www.theverge.com/2016/9/12/12889182/climate-change-global-warming-august-hottest-record-nasa

August 2016, .29F higher globally than the next highest August since 1880!

Ck. out the graph at the link above. Every month this year has been a new record except June when (as it appears on the graph) it tied the old record.

[Rob Dekker]

What ? Andrew Slater died ? No, no, no !
That can't be. He is a young guy, at the peak of his life, brilliant scientist. Famous for his work on all aspects of the Cryosphere, notably Arctic sea ice, permafrost and land snow. And a great contributor as IPCC WG1 author.
Please tell that this is not true ! Please !

[viddaloo]

Rest in peace. Feels very strange to have warched and shared his youtube so recently. On the other hand, no-one gets out of this situation (life) alive, I guess.

[NeilT]

RIP Andrew. I did a search and could not find anything. Seems to be private.

It is sad to see one of the younger generation who is doing such good work to be lost so young.

I feel for his family.

[NeilT]

Hans I think we were trying to establish that events prior to 2005 are different to events post 2005.

Post 2005 we see the cycle of large loss and re-growth typical of the 5 year cycles since.

As I see 2016 as being the same as 2006/2011, we would need to see 2017 and 2018 before that graph would start to match.

I see little benefit in trying to match 2016 with 2007 or 2012, clearly it was like neither year and it only saw such huge losses because of the extreme SST values and lack of ice.

2017 should be a very different animal leading to interesting results.

I'm more interested in when the heat trapped by the rapid onset of re-growth asserts itself towards the end of the month. Should produce some interesting phenomena. Or not, I don't know quite enough about what is happening on the ground/sea surface, right now, to guess.

[Hans Gunnstaddar]

"I see little benefit in trying to match 2016 with 2007 or 2012,"

I think there's a misunderstanding. I am not matching 2016 with 2007 & 2012. Instead what is being said in the video is there have been 5 year intervals between new record minimums. 2007 & 2012 are the 5th year events, whereas 2016 is the 4th year event. That puts 2017 as a 5th year event in the repeating pattern (presuming it continues).

So I guess you could say I am pre-matching 2017 with 2007 & 2012. Whether the prediction based on this repeating pattern is correct or not will be determined next melt season.

[viddaloo]

Hans, any theories about what causes the 2008, 2013 etc extreme rebounds, that is, if there is a cyclic pattern?